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2 years ago

How do u add and subtract negative fractions?

2 answers:

8 0

When you are adding or subtracting a negative fraction, you usually want to consider the numerator as negative. The method is just the same, except now you may need to add negative or positive numerators. The LCM of and is . To add the fractions with unlike denominators, rename the fractions with a common denominator.

Montano1993 [528]2 years ago

4 0

It’s just like solving a positive fraction find a common denominator and Add or subtract

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zhannawk [14.2K]

Answer:

might wanna take a picture instead...

7 0

1 year ago

In selecting a sulfur concrete for roadway construction in regions that experience heavy frost, it is important that the chosen

Lesechka [4]

Step-by-step explanation:

Given - In selecting a sulfur concrete for roadway construction in regions that experience heavy frost, it is important that the chosen concrete has a low value of thermal conductivity in order to minimize subsequent damage due to changing temperatures. Suppose two types of concrete, a graded aggregate and a no-fines aggregate, are being considered for a certain road. The table below summarizes data on thermal conductivity from an experiment carried out to compare the two types of concrete.

Type ni xi si

Graded 42 0.486 0.187

No-fines 42 0.359 0.158

To find - a. Formulate the above in terms of a hypothesis testing problem.

b. Give the test statistic and its reference distribution (under the null hypothesis).

c. Report the p-value of the test statistic and use it to assess the evidence that this sample provides on the scientific question of difference in mean conductivity of the two materials at the 5% level of significance.

Proof -

a.)

Hypothesis testing problem :

H0 : There is significant difference between mean conductivity for the graded concrete and mean conductivity for the no fines concrete.

H1 : There is no significant difference between mean conductivity for the graded concrete and mean conductivity for the no fines concrete.

Test statistic :

$Z = \frac{x_{1} - x_{2} }{\sqrt{\frac{s_{1} ^{2} }{n_{1}} + \frac{s_{2}^{2} }{n_{2}} } }$

$Z = \frac{0.486 - 0.359 }{\sqrt{\frac{0.03496 }{42} + \frac{0.02496 }{42} } }$

$Z = \frac{0.127 }{\sqrt{0.001468}}$

$Z = \frac{0.127 }{0.0377}$

⇒Z(cal) = 3.3687

Z(tab) = 1.96

As Z (cal) > Z(tab)

So, we reject H0 at 5% Level of significance

p-value = 0.99962

Hence

There is significant difference in mean conductivity at the two materials.

5 0

2 years ago

What is the standard for of (1 7i)(3-i)?

marissa [1.9K]

3 -1i + 21i -7i2 now you have to fix the last factore because you have to change the imaginery i this would give you the answer of 3 - 1i + 21i +7 now add common factor which would give you the final answer of 3 +20i +7

7 0

2 years ago

Write a slope-intercept equation for a line that passes through (-2,1) and (3,-14).

lesya [120]

The equation of the line that passes through (1, 5) and (-2, 14) in slope intercept form is y = -3x + 8.

5 0

1 year ago

Write a simplified polynomial expression in standard form to represent the area of the rectangle below.

Burka [1]

Area of Rectangle = length times width
lets say length = 2x-4
width = x+5

Note: you can switch these around, width could be 2x-4 and length could be x+5, it doesnt matter.

With that being said:
length * width = area
(2x-4)(x+5)=area
FOIL (First Outer Inner Last)
$2x^{2}+10x-4x-20=area$
Simplify:
$x^{2}+6x-20=area$

3 0

2 years ago